(1) Field of the Invention
This invention relates generally to submersible vessels and more particularly to a torpedo tube shutter door assembly.
(2) Description of the Prior Art
Submarines utilize a torpedo tube shutter door to fair the outer hull in the area where a weapon is launched from the vessel. Presently, there are primarily two shutter door configurations, a rotating shutter and a hinged shutter. In both arrangements, the torpedo tubes penetrate the vessel's pressure (inner) hull and a guide can guides the weapon as it travels out of the torpedo tube towards the outer hull and out to sea. The closable shutter door is provided to continue the egress path as the weapon travels from the vessel to the open sea.
A rotatable shutter is cone-shaped and rotates about an axis that is offset from the torpedo tube axis. In an open position, an opening in the large end of the shutter aligns a shutter inner guide surface with the torpedo tube axis in order to provide a clear path for the weapon. When the shutter is rotated to its closed position, the inner side of the shutter rotates to the outboard side of the vessel to provide a fairing with the outer hull. Since the rotatable shutter is cone-shaped, it occupies a great amount of space which otherwise could be utilized for other purposes.
The other type of shutter, the hinged shutter, is hinged at its forward end in a manner very similar to a standard door. The hinged shutter door is operated by a mechanism which utilizes a linkage system to open and close the shutter door. Like the rotatable shutter, this linkage system also occupies a great amount of space.
A problem associated with both of these shutter door arrangements is that the doors are very large (i.e., approximately fifteen feet long) because of the complex angle in which the torpedo tube axis intersects the outer hull. Also, the doors can only be supported at a limited number of points due to the enormity of their designs and the limited amount of space between the outer and inner hulls. There is presently a need for a shutter door assembly which is both compact and strong.